diff --git a/README.md b/README.md
index edeaa90c..aec271a6 100644
--- a/README.md
+++ b/README.md
@@ -60,7 +60,7 @@ $ npm run storybook
 ```
 we also use storyshot to do snapshot test with stories, make sure to run:
 ```
-$ npm test -- -u 
+$ npm test -- -u
 ```
 before pushing to update stories snapshots.
 Storybook will be available under /storybook/index.html after build.
@@ -84,6 +84,14 @@ Also, it will push the following custom variable to `dataLayer`;
 - `GA_TRACKING_ID` - see `PUBLIC_GA_TRACKING_ID`
 - `CURRENT_USER` - Current user object, set by `useCurrentUser`.
 
+Lastly, in Google Tag Manager we use `data-ga` property to track clicks.
+If user clicks a decendant of an React element with `data-ga` property,
+a click event will be sent to Google analytics with the written `data-ga`.
+(It doesn't even need to be rendered, we [setup the Google Tag Manager](https://github.com/cofacts/rumors-site/pull/254) to read private React instance)
+
+Also, if a component has its `displayName` set,
+a click event with that `displayName` is also sent to Google Analytics when any of its decendant is clicked.
+
 ## Design and Mockups
 
 * [真的假的 hackfoldr](http://beta.hackfoldr.org/rumors)
diff --git a/components/ArticleItem.js b/components/ArticleItem.js
index 4b280c40..f10e0b6d 100644
--- a/components/ArticleItem.js
+++ b/components/ArticleItem.js
@@ -147,7 +147,7 @@ export default function ArticleItem({
         content
       )}
       {isLink || (
-        <div className={classes.link}>
+        <div className={classes.link} data-ga="Bust hoax button">
           <Link href="/article/[id]" as={`/article/${article.id}`}>
             <a>{t`Bust Hoaxes`}</a>
           </Link>
@@ -162,6 +162,8 @@ export default function ArticleItem({
   );
 }
 
+ArticleItem.displayName = 'ArticleItem';
+
 ArticleItem.fragments = {
   ArticleItem: gql`
     fragment ArticleItem on Article {
diff --git a/components/ArticlePageLayout.js b/components/ArticlePageLayout.js
index 3b094030..e6d3040e 100644
--- a/components/ArticlePageLayout.js
+++ b/components/ArticlePageLayout.js
@@ -265,6 +265,7 @@ const FilterGroup = ({
             filters: filters.join(','),
           })
         }
+        data-ga="Filter(filter)"
       />
     )}
 
@@ -293,6 +294,7 @@ const FilterGroup = ({
               .join(','),
           })
         }
+        data-ga="Filter(category)"
       />
     )}
   </Filters>
@@ -444,6 +446,7 @@ function ArticlePageLayout({
           {lastCursorOfPage !== lastCursor && (
             <Box display="flex" pb={1.5} justifyContent="center">
               <button
+                data-ga="LoadMore"
                 type="button"
                 className={classes.loadMore}
                 onClick={() =>
@@ -481,6 +484,7 @@ function ArticlePageLayout({
       <Fab
         variant="extended"
         aria-label="filters"
+        data-ga="Mobile filter button"
         className={classes.openFilter}
         onClick={() => setFiltersShow(!showFilters)}
       >
@@ -502,6 +506,7 @@ function ArticlePageLayout({
         <Fade in={showFilters}>
           <Box position="relative">
             <FilterGroup
+              data-ga="Mobile filter view"
               options={options}
               categories={categories}
               defaultFilters={defaultFilters}
diff --git a/components/ExpandableText.js b/components/ExpandableText.js
index de958c3e..05c17cb0 100644
--- a/components/ExpandableText.js
+++ b/components/ExpandableText.js
@@ -32,6 +32,8 @@ const ToggleButton = withStyles({
   </button>
 ));
 
+ToggleButton.displayName = 'ExpandableTextToggleButton';
+
 const ExpandableText = ({ className, lineClamp, wordCount = 40, children }) => {
   const [expanded, setExpanded] = useState(false);
   const [height, setHeight] = useState(0);
diff --git a/components/FeedDisplay.js b/components/FeedDisplay.js
index 9edf6657..eb03642a 100644
--- a/components/FeedDisplay.js
+++ b/components/FeedDisplay.js
@@ -103,4 +103,6 @@ function FeedDisplay({ feedUrl }) {
   );
 }
 
+FeedDisplay.displayName = 'FeedDisplay';
+
 export default FeedDisplay;
diff --git a/components/Filters.js b/components/Filters.js
index c64f614f..053dff41 100644
--- a/components/Filters.js
+++ b/components/Filters.js
@@ -161,7 +161,11 @@ export function Filter({
       </div>
       {expandable && (
         <div className={classes.expand}>
-          <button type="button" onClick={() => setExpand(e => !e)}>
+          <button
+            type="button"
+            onClick={() => setExpand(e => !e)}
+            data-ga="FilterExpandButton"
+          >
             {expand ? (
               <>
                 {t`Collapse`}
diff --git a/components/ReplyFeedback.js b/components/ReplyFeedback.js
index ef0c4f5a..c8a39034 100644
--- a/components/ReplyFeedback.js
+++ b/components/ReplyFeedback.js
@@ -291,6 +291,7 @@ function ReplyFeedback({
         className={cx(classes.vote, ownVote === 'UPVOTE' && classes.voted)}
         type="button"
         onClick={e => openVotePopover(e, 'UPVOTE')}
+        data-ga="Upvote"
       >
         <ThumbUpIcon className={classes.outlinedIcon} />
       </button>
@@ -298,10 +299,11 @@ function ReplyFeedback({
         className={cx(classes.vote, ownVote === 'DOWNVOTE' && classes.voted)}
         type="button"
         onClick={e => openVotePopover(e, 'DOWNVOTE')}
+        data-ga="Downvote"
       >
         <ThumbDownIcon className={classes.outlinedIcon} />
       </button>
-      <div className={classes.buttonGroup}>
+      <div className={classes.buttonGroup} data-ga="Number display">
         <button className={classes.vote} type="button">
           {positiveFeedbackCount}
           <ThumbUpIcon className={classes.icon} />
@@ -425,6 +427,8 @@ function ReplyFeedback({
   );
 }
 
+ReplyFeedback.displayName = 'ReplyFeedback';
+
 ReplyFeedback.fragments = {
   ArticleReplyFeedbackData,
   ArticleReplyFeedbackForUser,
diff --git a/components/ReplyItem.js b/components/ReplyItem.js
index ee806e8d..3829c342 100644
--- a/components/ReplyItem.js
+++ b/components/ReplyItem.js
@@ -126,6 +126,8 @@ function ReplyItem({
   );
 }
 
+ReplyItem.displayName = 'ReplyItem';
+
 ReplyItem.fragments = {
   ReplyItem: gql`
     fragment ReplyItem on Reply {
diff --git a/components/SortInput.js b/components/SortInput.js
index 487e3b38..640ed2fd 100644
--- a/components/SortInput.js
+++ b/components/SortInput.js
@@ -63,4 +63,6 @@ function SortInput({ orderBy, onChange = () => {}, options }) {
   );
 }
 
+SortInput.displayName = 'SortInput';
+
 export default SortInput;
diff --git a/components/TimeRange.js b/components/TimeRange.js
index 8a992914..90a03427 100644
--- a/components/TimeRange.js
+++ b/components/TimeRange.js
@@ -181,7 +181,11 @@ function TimeRange({ onChange = () => null, range }) {
         onClose={closeMenu}
       >
         {options.map(option => (
-          <MenuItem key={option.value} onClick={select(option.value)}>
+          <MenuItem
+            key={option.value}
+            onClick={select(option.value)}
+            data-ga={`MenuItem(${option.value})`}
+          >
             {option.label}
           </MenuItem>
         ))}
@@ -190,4 +194,6 @@ function TimeRange({ onChange = () => null, range }) {
   );
 }
 
+TimeRange.displayName = 'TimeRange';
+
 export default TimeRange;
diff --git a/lib/useCurrentUser.js b/lib/useCurrentUser.js
index 7eb9bd18..36fb8f53 100644
--- a/lib/useCurrentUser.js
+++ b/lib/useCurrentUser.js
@@ -1,7 +1,7 @@
 import { useEffect } from 'react';
 import { useLazyQuery } from '@apollo/react-hooks';
 import gql from 'graphql-tag';
-import { usePushToDataLayer } from './gtm';
+import { pushToDataLayer } from './gtm';
 
 export const CurrentUser = gql`
   fragment CurrentUser on User {
@@ -22,10 +22,21 @@ const USER_QUERY = gql`
 /**
  * Loads currentUser on browser load. Should load from cache first.
  */
+let pushDataLayerHandle;
 function useCurrentUser() {
-  const [loadUser, { data }] = useLazyQuery(USER_QUERY);
+  const [loadUser, { data }] = useLazyQuery(USER_QUERY, {
+    onCompleted(data) {
+      // If multiple component with useCurrentUser() is mounted in the same time,
+      // onCompleted will be invoked multiple times.
+      //
+      // We use setTimeout to get rid of duplicated onCompleted calls.
+      clearTimeout(pushDataLayerHandle);
+      pushDataLayerHandle = setTimeout(() => {
+        pushToDataLayer({ CURRENT_USER: data?.GetUser });
+      }, 10);
+    },
+  });
   useEffect(() => loadUser(), []);
-  usePushToDataLayer(data?.GetUser, { CURRENT_USER: data?.GetUser });
 
   return data?.GetUser;
 }